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Diffstat (limited to 'contrib/llvm/lib/Support/BinaryStreamReader.cpp')
-rw-r--r-- | contrib/llvm/lib/Support/BinaryStreamReader.cpp | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/BinaryStreamReader.cpp b/contrib/llvm/lib/Support/BinaryStreamReader.cpp new file mode 100644 index 0000000..e00527f --- /dev/null +++ b/contrib/llvm/lib/Support/BinaryStreamReader.cpp @@ -0,0 +1,149 @@ +//===- BinaryStreamReader.cpp - Reads objects from a binary stream --------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Support/BinaryStreamReader.h" + +#include "llvm/Support/BinaryStreamError.h" +#include "llvm/Support/BinaryStreamRef.h" + +using namespace llvm; +using endianness = llvm::support::endianness; + +BinaryStreamReader::BinaryStreamReader(BinaryStreamRef Ref) : Stream(Ref) {} + +BinaryStreamReader::BinaryStreamReader(BinaryStream &Stream) : Stream(Stream) {} + +BinaryStreamReader::BinaryStreamReader(ArrayRef<uint8_t> Data, + endianness Endian) + : Stream(Data, Endian) {} + +BinaryStreamReader::BinaryStreamReader(StringRef Data, endianness Endian) + : Stream(Data, Endian) {} + +Error BinaryStreamReader::readLongestContiguousChunk( + ArrayRef<uint8_t> &Buffer) { + if (auto EC = Stream.readLongestContiguousChunk(Offset, Buffer)) + return EC; + Offset += Buffer.size(); + return Error::success(); +} + +Error BinaryStreamReader::readBytes(ArrayRef<uint8_t> &Buffer, uint32_t Size) { + if (auto EC = Stream.readBytes(Offset, Size, Buffer)) + return EC; + Offset += Size; + return Error::success(); +} + +Error BinaryStreamReader::readCString(StringRef &Dest) { + uint32_t OriginalOffset = getOffset(); + uint32_t FoundOffset = 0; + while (true) { + uint32_t ThisOffset = getOffset(); + ArrayRef<uint8_t> Buffer; + if (auto EC = readLongestContiguousChunk(Buffer)) + return EC; + StringRef S(reinterpret_cast<const char *>(Buffer.begin()), Buffer.size()); + size_t Pos = S.find_first_of('\0'); + if (LLVM_LIKELY(Pos != StringRef::npos)) { + FoundOffset = Pos + ThisOffset; + break; + } + } + assert(FoundOffset >= OriginalOffset); + + setOffset(OriginalOffset); + size_t Length = FoundOffset - OriginalOffset; + + if (auto EC = readFixedString(Dest, Length)) + return EC; + + // Now set the offset back to after the null terminator. + setOffset(FoundOffset + 1); + return Error::success(); +} + +Error BinaryStreamReader::readWideString(ArrayRef<UTF16> &Dest) { + uint32_t Length = 0; + uint32_t OriginalOffset = getOffset(); + const UTF16 *C; + while (true) { + if (auto EC = readObject(C)) + return EC; + if (*C == 0x0000) + break; + ++Length; + } + uint32_t NewOffset = getOffset(); + setOffset(OriginalOffset); + + if (auto EC = readArray(Dest, Length)) + return EC; + setOffset(NewOffset); + return Error::success(); +} + +Error BinaryStreamReader::readFixedString(StringRef &Dest, uint32_t Length) { + ArrayRef<uint8_t> Bytes; + if (auto EC = readBytes(Bytes, Length)) + return EC; + Dest = StringRef(reinterpret_cast<const char *>(Bytes.begin()), Bytes.size()); + return Error::success(); +} + +Error BinaryStreamReader::readStreamRef(BinaryStreamRef &Ref) { + return readStreamRef(Ref, bytesRemaining()); +} + +Error BinaryStreamReader::readStreamRef(BinaryStreamRef &Ref, uint32_t Length) { + if (bytesRemaining() < Length) + return make_error<BinaryStreamError>(stream_error_code::stream_too_short); + Ref = Stream.slice(Offset, Length); + Offset += Length; + return Error::success(); +} + +Error BinaryStreamReader::readSubstream(BinarySubstreamRef &Stream, + uint32_t Size) { + Stream.Offset = getOffset(); + return readStreamRef(Stream.StreamData, Size); +} + +Error BinaryStreamReader::skip(uint32_t Amount) { + if (Amount > bytesRemaining()) + return make_error<BinaryStreamError>(stream_error_code::stream_too_short); + Offset += Amount; + return Error::success(); +} + +Error BinaryStreamReader::padToAlignment(uint32_t Align) { + uint32_t NewOffset = alignTo(Offset, Align); + return skip(NewOffset - Offset); +} + +uint8_t BinaryStreamReader::peek() const { + ArrayRef<uint8_t> Buffer; + auto EC = Stream.readBytes(Offset, 1, Buffer); + assert(!EC && "Cannot peek an empty buffer!"); + llvm::consumeError(std::move(EC)); + return Buffer[0]; +} + +std::pair<BinaryStreamReader, BinaryStreamReader> +BinaryStreamReader::split(uint32_t Off) const { + assert(getLength() >= Off); + + BinaryStreamRef First = Stream.drop_front(Offset); + + BinaryStreamRef Second = First.drop_front(Off); + First = First.keep_front(Off); + BinaryStreamReader W1{First}; + BinaryStreamReader W2{Second}; + return std::make_pair(W1, W2); +}
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